Expert: Paul Soderman - 3/14/2007

Question
I'm trying to build some kind of herb dryer, crucial part of it is a fan, and I need some formulae for calculating air flow and/or air speed depending of shape, RPM, power and other factors of the propeler.

thank you

Answer
Nighthawk - predicting fan performance can be done, but it is a difficult process that requires a number of complicated computations.  It would be a lot easier to search the literature or web and find a fan that has the size and power required close to what you want, and then get the performance curves from the manufacturer.  Those might be on line also.  Every commercial fan and propeller has been tested and documented for air flow and pressure delivery,  Try Google.

Paul